Lederberg, Joshua (1925–2008)

Joshua Lederberg was an American geneticist at Stanford University who shared the 1958 Nobel Prize
in Physiology or Medicine with George Beadle and Edward Tatum for discovering the mechanisms of genetic recombination
in bacteria. With Tatum, Lederberg showed
that the offspring of different mutants of Escherichia
coli had genes recombined from those of the original generation,
thus establishing the sexuality of E. coli. Later he showed that
genetic information could be carried between Salmonella by certain
bacterial viruses.

In 1958, while at the University of Wisconsin (where he was chairman of
the medical genetics department), Lederberg was the first to raise the issue
of biological contamination by space
missions.1 He was subsequently appointed chairman of WESTEX and then of the Space Science Board's Committee 14 on Exobiology. In 1960, Lederberg
introduced the term "exobiology,"2 and in 1961 was among the group of researchers who attended the first SETI conference at Green Bank.3